Calgary, AB (My Sportsbook) - Australia's Anna Rawson fired a seven-under 64 to take the first-round lead Thursday at the CN Canadian Women's Open.

Rawson carded a career-low round on the LPGA Tour to finish a shot ahead of Suzann Pettersen for her second 18-hole lead.

World No. 1 Lorena Ochoa, the 2007 champion, and Amanda Blumenherst were another stroke further back at five-under 66, while Japanese star Momoko Ueda led a four-way tie at 67.

While many top players struggled Thursday -- Michelle Wie opened with a 76 -- Rawson thrived by being among the best prepared players in the field.

Rawson played two practice rounds at Priddis Greens -- altitude around 4,000 feet -- just to get the feel of the course and adjust to the high elevation.

It paid off for the 28-year-old Australian, who is perhaps better-known for her part-time modeling career than her success on the golf course.

"We didn't have any problems today," she said. "I over-shot one green and [it was] a perfect shot. I was just in the rough."

Relying on strong iron play, Rawson collected four birdies and two bogeys and posted a 33 on the front nine. But it was the hilly back side of the course where she really caught fire.

Trying to stay in the moment and not get ahead of herself, Rawson birdied five holes and shot a 31 on the back nine, getting off to a hot start with a lob- wedge to just inches at the 10th.

She added birdies at the 12th, 14th, 15th and 17th holes to better her career- low score by a shot.

Rawson's previous best was a 65 in the final round of the State Farm Classic in June -- also seven-under par.

"I feel great on this golf course," said Rawson. "I really like all the holes. I feel like you can birdie every one, depending where they put the pins. But I think I've just got a good grasp for it in the practice rounds."

Rawson, who is languishing at 110th on the money list after making just four cuts in her previous 13 starts this season, began working with a sports psychologist about a month ago.

"I think this year has just been terrible mentally," she said. "Like, I've just had the worst head that you could ever imagine. I don't even want to tell you what's been going through my head; it's that bad.

"I thought about everything that I shouldn't. I really haven't hit the ball that bad. I just haven't been here. I haven't been enjoying it, I haven't been out here."